Report on the intercomparison runs for the determination of trace and minor elements in cabbage material. IAEA-359

In 1989, the IAEA decided to produce a cabbage plant reference material that could be characterised for certain agrochemical residues. The cabbage plants (Brassica oleracea var. Sabauda) were grown from seed in Seibersdorf, Austria. The plants were treated with ten different agrochemical products during their growing period. Subsequently, it was decided that the material would also be valuable as a reference material for trace element analysis and quality control purposes. The property values for the trace metal content of the cabbage material, designated IAEA 359, were to be ascribed on the basis of information received from international intercomparison exercises. In parallel, it was decided to despatch the material as part of a joint IAEA-NIST (National Institute of Standards and Technology, USA) project to certify the trace and minor element contents of a spinach reference material (NIST 1570a), in which it was to serve as a quality control material. A similar rationale was used to justify inclusion of IAEA 359 in a small scale exercise for a preliminary characterisation of another IAEA reference material, IAEA 336 Lichen. Between 1992 and 1993, the material was used in 4 projects (2 large scale and 2 smaller scale) where its trace element contents were determined. This report deals with the statistical evaluation of the pooled analytical data from these exercises